Phosphor, light emitting device package, and electronic apparatus

ABSTRACT

A light-emitting device package includes a light emitting device configured to emit light of a first main wavelength band within a visible light wavelength band; a first phosphor including a first core and a first shell, the first core including a fluorescent material capable of emitting light of a first wavelength band different from the first main wavelength band of the light emitted from the light emitting device, wherein the first shell eliminates light of a specific wavelength band or attenuates an intensity of light of the specific wavelength band from the light of the first wavelength band to emit light of a second main wavelength band within the visible light wavelength band; and a second phosphor including a second core, wherein the first core is heavier than the first shell.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of copending U.S. patent applicationSer. No. 15/842,012, filed on Dec. 14, 2017, which claims priority under35 U.S.C. § 119(a) to Korean Patent Application No. 10-2017-0018945,filed on Feb. 10, 2017, all of these applications are herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a phosphor, a light-emitting devicepackage, and an electronic apparatus.

2. Description of the Related Art

Nowadays, a display apparatus utilizes as a light source alight-emitting device package including a light-emitting device such asa light-emitting diode (LED) and at least one phosphor. Conventionalphosphors used in light-emitting device packages have a problem due toemitted spectrums being wider than wavelength bands corresponding tocolors of light intended to be emitted. As a result of the phosphorsemitting light spectrums wider than desired, the light emitted by thephosphors is impure. The light emitted by the phosphors is a mixtureincluding undesired colors. Color reproduction capability of the displayapparatus employing as the light source the light-emitting devicepackage of related art is degraded due to the decrease of the gamut ofpure colors of emitted light.

SUMMARY OF THE INVENTION

Accordingly, an aspect of the present invention is to provide a phosphorhaving an excellent gamut of pure colors.

Another aspect of the present invention is to provide a light-emittingdevice package including a phosphor having an excellent gamut of purecolors.

A further aspect of the present invention is to provide an electronicapparatus which employs as a light source a light-emitting devicepackage including a phosphor emitting an excellent gamut of pure colorsof light. The electronic apparatus of the present invention including aphosphor that has a core-shell structure exhibits a high capability forreproducing colors.

An aspect of the present invention is to provide a phosphor having acore-shell structure, a light-emitting device package utilizing thesame, and an electronic apparatus, such as a display apparatus and anillumination apparatus, using the same.

Another aspect of the present invention is to provide a phosphorincluding a core that includes a fluorescent material capable ofabsorbing external light and emitting light of a first wavelength band.The phosphor includes least one shell, applied to a surface of the core,capable of eliminating light of a specific wavelength band from thelight of the first wavelength band or emitting light in which anintensity of the light of the specific wavelength band is attenuated.

The core in the phosphor may be heavier than the shell, which may have aweight ratio of 0.6 or less with respect to the core. The weight ratioof the shell to the core in the phosphor enables light of selectivewavelengths (e.g., wavelengths in a specific wavelength band)corresponding to a part of light (e.g., visible light) emitted from thecore to be eliminated, or attenuated in intensity when passing throughthe shell.

The shell of the phosphor having a core-shell structure may act as aselective wavelength absorption layer or a selective wavelengthabsorption coating layer. The shell in the phosphor may have a thicknesssmaller than a distance from a center of the core to a surface of thecore. The shell in the phosphor may have a thickness from 2,000nm-500,000 nm.

A further aspect of the present invention is to provide a light-emittingdevice package including a first light emitting device for emittinglight of a first main wavelength band within a visible light wavelengthband; and a first phosphor including a first core and at least one firstshell applied to a surface of the first core, the first core including afluorescent material capable of emitting light of a first wavelengthband different from the first main wavelength band of the light emittedfrom the first light emitting device, the first shell eliminating lightof a first specific wavelength band or attenuating an intensity of lightof a first specific wavelength band from the light of the firstwavelength band to emit light of a second main wavelength band withinthe visible light wavelength band.

The first shell applied to the surface of the first core may include amaterial exhibiting a first light transmission property of attenuatingan intensity of the light of the first specific wavelength band to lessthan a threshold intensity and outputting the attenuated light after theincidence of light.

In the first phosphor, the first shell may have a weight ratio of 0.6 orless with regard to the first core. A weight ratio of the first shell tothe first core may be set in such a manner that the intensityattenuation of the light of a first specific wavelength band is acertain level or greater. A thickness of the first shell may range from2,000 nm-500,000 nm, and may be determined such that the intensityattenuation of the light of a first specific wavelength band is acertain level or greater.

In the first phosphor, the first shell may include at least one rareearth metal. The first core includes at least one selected from among(Sr,Ba,Mg)2SiO4:Eu, A15Lu3O12:Ce, (Sr,Ba,Mg)2SiO4:Eu, Y3Al5O12:Ce,La3Si6N11:Ce, (Sr,Ba,Eu)2SiO4:Eu, β-Sialon:Si6-zAlzOzN8-z:Eu,Lu3Al5O12:Ce, (Lu, Gd)3Al5O12:Ce, and Y3Al5O12:Ce (0.01<z<10).

The light-emitting device package may further include a second phosphorcomposed of a second core and a second shell applied to a surface of thesecond core. The second core includes a fluorescent material capable ofemitting light of a second wavelength band different from the first mainwavelength band of the light emitted from the first light emittingdevice. The second shell eliminates light of a second specificwavelength band or attenuates an intensity of light of a second specificwavelength band from the light of the second wavelength band to emitlight of a third main wavelength band within the visible lightwavelength band.

In the second phosphor, the second shell may include a materialexhibiting a second light transmission property of attenuating anintensity of the light of the second specific wavelength band to lessthan a threshold intensity and outputting the attenuated light after theincidence of light.

The first specific wavelength band may be identical to or overlap withthe second specific wavelength band. In addition, the first wavelengthband may be different from the second specific wavelength band.

A weight ratio of the first shell to the first core in the firstphosphor may be identical to that of the second shell to the second corein the second phosphor. A weight ratio of the first shell to the firstcore in the first phosphor may be different from that of the secondshell to the second core in the second phosphor.

In the second phosphor, the second shell may have a weight ratio of 0.6or less with regard to the second core. The weight ratio of the secondshell to the second core in the second phosphor may be set in such amanner that the intensity of attenuation of the light of a secondspecific wavelength band is a certain level or greater.

The first shell of the first phosphor may be identical in thickness tothe second shell of the second phosphor.

The first shell of the first phosphor may be different in thickness fromthe second shell of the second phosphor.

The first shell of the first phosphor may be thicker than the secondshell of the second phosphor.

The second shell of the second phosphor may range in thickness from2,000 nm-500,000 nm.

In the second phosphor, the thickness of the second shell may bedetermined in such a manner that the intensity attenuation of the lightof a second specific wavelength band is a certain level or greater.

The second shell of the second phosphor may include at least one rareearth element.

The second core of the second phosphor may include at least one selectedfrom among (Sr,Ba,Mg)3SiO5:Eu, (Sr,Ca)AlSiN3:Eu, CaAlSiN3:Eu,MyM′z(Si,B,Al)5OxN8-x:Eu, MSil-zAlzOzN2-z:Eu,α-Sialon:CaxEuy(Si,Al)12(O,N)16, S—CaAlSiN, CaAlSiN, (Sr,Ca)AlSiN3:Eu,K2SiF6:Mn4+ (0.01<x<10, 0.01<y<20, 0.01<z<10, M and M′ are each selectedfrom among Ca, Sr, and Ba).

The light-emitting device package may further include a second phosphorcomposed of a second core including a fluorescent material capable ofemitting light of a second wavelength band different from the first mainwavelength band of the light emitted from the first light emittingdevice.

For example, the first light emitting device may be a blue lightemitting device capable of emitting blue light. The first phosphor maybe a green phosphor capable of emitting green light or a red phosphorcapable of emitting red light. The second phosphor may be a red phosphoror a green phosphor.

The light-emitting device package, which includes the first lightemitting device, may further include a second light emitting devicecapable of emitting light of a third main wavelength band within thevisible light wavelength band. The second light emitting device may be agreen light emitting device capable of emitting green light or a redlight emitting device capable of emitting red light.

Still another aspect of the present invention is to provide anelectronic apparatus including a light emitting device package includinga first light emitting device for emitting light of a first mainwavelength band within a visible light wavelength, and a first phosphorfor emitting light of a second main wavelength band different from thefirst main wavelength band. The electronic apparatus includes a drivingcircuit for driving the first light emitting device.

In the electronic apparatus, the first phosphor includes a first coreincluding a fluorescent material capable of emitting light of a firstwavelength band different from the first main wavelength band of thelight emitted from the first light emitting device; and at least onefirst shell, applied to a surface of the first core, capable of emittinglight of the second main wavelength band within the visible lightwavelength band by eliminating the light of the first specificwavelength band or by attenuating an intensity of the light of the firstspecific wavelength from the light of the first wavelength band.

A still further aspect of the present invention is to provide anelectronic apparatus including a phosphor composed of a core and atleast one shell applied to a surface of the core. The core includes afluorescent material capable of emitting light of a wavelength banddifferent from a first pure color wavelength band, and the shell iscapable of emitting light of a second pure color wavelength band withina visible color wavelength band by eliminating light of a specificwavelength band or by attenuating an intensity of light of a specificwavelength from the light emitted from the core.

According to some embodiments thereof, the present invention can providea phosphor that exhibits an excellent gamut of pure colors by means of acore-shell structure.

According to some embodiments thereof, the present invention can providea light-emitting device package comprising a phosphor having acore-shell structure.

According to some embodiments thereof, the present invention can providean electronic apparatus that employs as a light source a light-emittingdevice package inclusive of a phosphor having a core-shell structure toexhibit high color reproduction capability.

According to some embodiments thereof, the present invention provides anelectronic apparatus that uses a phosphor having a core-shell structureto exhibit high color reproduction capability.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram illustrating a phosphor having a core-shellstructure according to some embodiments of the present invention;

FIG. 2 is a view showing light transmission properties of the shell in aphosphor having a core-shell structure according to some embodiments ofthe present invention;

FIG. 3 shows various forms of the phosphor having a core-shell structureaccording to some embodiments of the present invention;

FIG. 4 is a view elucidating the use of the phosphor having a core-shellstructure according to some embodiments of the present invention;

FIG. 5 is a view illustrates three types of light emitting devicepackages utilizing an phosphor having a core-shell structure accordingto some embodiments of the present invention.

FIGS. 6 and 7 are diagrams respectively showing light-emitting devicepackage of Type 1-a including one kind of light emitting device (bluelight emitting device) and two kinds of phosphors (red phosphors andgreen phosphors), and red phosphors and green phosphors, each having acore-shell structure;

FIGS. 8 and 9 are diagrams respectively showing a light-emitting devicepackage of Type 1-b including one kind of light emitting device (bluelight emitting device) and two kinds of phosphors (green phosphors andred phosphors), and a green phosphor having a core-shell structure and ared phosphor having a structure according to the present application.

FIGS. 10 and 11 are diagrams respectively showing a light-emittingdevice package of Type 1-c including one kind of light emitting device(blue light emitting device) and two kinds of phosphors (red phosphorsand green phosphors), and a red phosphor having a core-shell structureand a green phosphor having a structure to the present application.

FIGS. 12 and 13 are diagrams respectively showing a light-emittingdevice package of Type 2 including two kinds of light emitting devices(blue light emitting device and red light emitting device) and one kindof phosphor (green phosphor), and a green phosphor having a core-shellstructure;

FIGS. 14 and 15 are diagrams respectively showing a light-emittingdevice package of Type 3 including two kinds of light emitting devices(blue light emitting device and green light emitting devices) and onekind of phosphor (red phosphor), and a red phosphor having a core-shellstructure;

FIG. 16 shows emission spectra of a light-emitting device package inwhich the gamut of pure colors is improved as the core-shell structureof the green phosphor eliminates a green-red (G-R) mixed color noise inaccordance with some embodiment of the present invention;

FIG. 17 shows emission spectra of the light-emitting device package inwhich the gamut of pure colors is improved as the core-shell structureof a red phosphor eliminates a G-R mixed color noise in accordance withsome embodiment of the present invention;

FIG. 18 shows emission spectra of the light-emitting device package inwhich the gamut of pure colors is improved as the core-shell structureof a green phosphor eliminates a blue-green (B-G) mixed color noise inaccordance with some embodiment of the present invention;

FIGS. 19 and 20 are schematic views illustrating a display apparatusesincluding two types of backlight units that utilize a light-emittingdevice package according to some embodiments of the present invention;

FIG. 21 is a schematic view illustrating an illumination apparatus thatutilizes a light-emitting device package according to some embodimentsof the present invention; and

FIG. 22 is a view illustrating a display apparatus further including asupplementary color conversion layer that utilizes phosphors in acore-shell structure according to some embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Hereinafter, some embodiments of the present invention will be describedin detail with reference to the accompanying illustrative drawings. Indesignating elements of the drawings by reference numerals, the sameelements will be designated by the same reference numerals although theyare shown in different drawings. Further, in the following descriptionof the present invention, a detailed description of known functions andconfigurations incorporated herein will be omitted when it may obfuscatethe subject matter of the present invention.

In addition, terms, such as first, second, A, B, (a), (b) or the likemay be used herein when describing components of the present invention.Each of these terminologies is not used to define an essence, order orsequence of a corresponding component but used merely to distinguish thecorresponding component from other component(s). In the case that it isdescribed that a certain structural element “is connected to”, “iscoupled to”, or “is in contact with” another structural element, itshould be interpreted that another structural element may “be connectedto”, “be coupled to”, or “be in contact with” the structural elements aswell as that the certain structural element is directly connected to oris in direct contact with another structural element.

FIG. 1 is a diagram illustrating a phosphor (P) having a core-shellstructure according to some embodiments of the present invention andFIG. 2 is a view showing light transmission properties of the shell (PS)in a phosphor (P) having a core-shell structure according to someembodiments of the present invention.

With reference to FIG. 1, the phosphor (P) according to some embodimentsof the present invention has a core-shell structure composed of a core(PC) including a phosphorescent material, and at least one shell (PS)wrapping the core (PC).

The core (PC) of the phosphor (P) includes a phosphorescent materialthat absorbs first pure-color light of a first pure-color wavelengthband and emits the light of a wavelength band different from the firstpure color wavelength band. As used herein, the expression “twowavelength bands are different from each other” is intended to encompassboth a case where two wavelength bands do not overlap each other at alland a case where two wavelength bands overlap each other in part.

At least one shell (PS) of the phosphor (P) is applied to the surface ofthe core (PC) and can emit second pure-color light of a secondpure-color wavelength band by eliminating the light of a specificwavelength band or attenuating the intensity of the light of a specificwavelength band from the light of wavelength bands emitted from the core(PC).

The shell (PS) of the phosphor (P) includes a material having the lighttransmission property of attenuating the intensity of the light of aspecific wavelength band (e.g., B-G mixed color wavelength band or G-Rmixed color wavelength band) to less than a threshold intensity andoutputting the attenuated light after the incidence of light.

Next, FIG. 2 is a graph showing light transmission properties of theshell (PS) of the phosphor (P), in which when light with intensity Sinis incident on the shell (PS), the intensity Sout of the light (e.g.,output light) emitted from the shell (PS) is depicted depending on thewavelengths of the incident light.

When incident light with wavelengths outside of a specific wavelengthband (Wc) is irradiated to the shell (PS), the intensity Sout of thelight emitted from the shell (PS) may be lowered below the intensity Sinof the incident light by normal attenuation, but still stays higher thana threshold intensity Sth.

After light with wavelengths outside of a specific wavelength band (Wc)is incident on the shell (PS), the light intensity attenuation(Sin-Sout) in the shell (PS) may remain less than a certain level (K).When light with a wavelength inside of a specific wavelength band (Wc)is incident on the shell (PS), the intensity Sout of the light emittedfrom the shell (PS) is lowered below a threshold intensity Sth as wellas the intensity Sin of the incident light.

After light with wavelengths inside of a specific wavelength band (Wc)is incident on the shell (PS), the light intensity attenuation(Sin-Sout) in the shell (PS) may be a certain level (K) or greater. Theshell (PS) of the phosphor (P) attenuates the intensity of the light ofa specific wavelength band (Wc) or removes the light of a specificwavelength band (Wc) by absorbing the light of the specific wavelengthband (Wc).

The first pure-color light absorbed by the core (PC) of the phosphor (P)may be pure blue light. The second pure-color light emitted from theshell (PS) of the phosphor (P) may be pure green or red light.

In the case where the core (PC) of the phosphor (P) absorbs pure bluelight and the shell (PS) of the phosphor (P) emits pure green light bycontrolling a mixed color range of green and red lights, correspondingwavelength properties are associated with the phosphor (P). The firstpure-color wavelength band of the light absorbed by the core (PC) of thephosphor (P) is a wavelength band of pure blue light (hereinafter bluewavelength band), covering a range of approximately 380-500 nm.

The wavelength band of the light that the core (PC) of the phosphor (P)emits may include a wavelength band of pure green light (hereinaftergreen wavelength band) that is approximately 500-550 nm, and may includea wavelength band of green and red color-mixed light (hereinafter G-Rmixed color wavelength band) that is approximately 550-600 nm and rangesfrom approximately 500-600 nm. 500 to 600 nm. The specific wavelengthband eliminated or attenuated by the shell (PS) of the phosphor (P) maybe the G-R mixed color wavelength band and may range from approximately550 to 600 nm.

The second pure-color wavelength band of the light emitted from theshell (PS) of the phosphor (P) may be a green wavelength band rangingfrom approximately 500-550 nm.

In the case where the core (PC) of the phosphor (P) absorbs pure bluelight and the shell (PS) of the phosphor (P) emits pure red light bycontrolling a mixed color range of green and red lights, wavelengthproperties associated with the phosphor (P) are as follows.

The first pure-color wavelength band of the light absorbed by the core(PC) of the phosphor (P) is a blue wavelength band, covering a range ofapproximately 380-500 nm.

The wavelength band of the light that the core (PC) of the phosphor (P)emits may include a wavelength band of pure red light (hereinafter redwavelength band) which is approximately 600-700 nm, and may include aG-R mixed color wavelength band which is approximately 550-600 nm andranges from approximately 550-700 nm.

Meanwhile, the specific wavelength band eliminated or attenuated by theshell (PS) of the phosphor (P) may be the G-R mixed color wavelengthband and may range from approximately 550-600 nm.

The second pure-color wavelength band of the light emitted from theshell (PS) of the phosphor (P) may be a red wavelength band ranging fromapproximately 600-700 nm.

In the case where the core (PC) of the phosphor (P) absorbs pure bluelight and the shell (PS) of the phosphor (P) emits pure green light bycontrolling a mixed color range of green and red lights, wavelengthproperties associated with the phosphor (P) are as follows.

The first pure-color wavelength band of the light absorbed by the core(PC) of the phosphor (P) is a wavelength band of pure blue light(hereinafter referred to as “blue wavelength band”), covering a range ofapproximately 380-500 nm.

The wavelength band of the light that the core (PC) of the phosphor (P)emits may include a wavelength band of pure green light (hereinafterreferred to as “green wavelength band”, approximately 500-550 nm) and awavelength band of green and blue color-mixed light (hereinafterreferred to as “B-G mixed color wavelength band”, approximately 480-500nm), ranging from approximately 480-550 nm.

Meanwhile, the specific wavelength band eliminated or attenuated by theshell (PS) of the phosphor (P) may be the B-G mixed color wavelengthband and may range from approximately 480-500 nm.

The second pure-color wavelength band of the light emitted from theshell (PS) of the phosphor (P) may be a green wavelength band rangingfrom approximately 500-550 nm.

The phosphor (P) having the core-shell structure with the core (PC) thatmay be heavier than the shell (PS) can emit the pure-color light of apure wavelength band. For example, the weight ratio of the shell (PS) tothe core (PC) in the phosphor (P) may be 0.6 or less. The weight of theshell (PS) may be set to be 0.6 or less when the weight of the core (PC)is 1.

The phosphor (P) according to the present invention solves a problem ofthe phosphor (P) according to related art. The problem of the phosphor(P) according to related art, when the weight ratio of the shell (PS) tothe core (PC) in the phosphor (P) is more than 0.6, the plausibilitythat the shell (PS) emits purer color light is increased. The lightemitted from the core (PC) in the phosphor (P) according to related artmay penetrate at low efficiency through the shell (PS), resulting ingreatly degrading luminance performance.

The phosphor (P) having a core-shell structure according to the presentinvention with a shell (PS)-to-core (PC) weight ratio of 0.6 or less mayallow for the emission of pure color light without degrading luminanceperformance. In other words, by providing the phosphor (P) with theshell (PS)-to-core (PC) weight ratio of 0.6 or less, the presentinvention avoids the degrading luminance performance of the phosphor (P)according to related art.

In the phosphor (P) of the present invention having a core-shellstructure, the thickness (T) of the shell (PS) may be smaller than thedistance (R) from the center (O) of the core (PC) to the surface of thecore (PC). For example, the shell (PS), which may range in thicknessfrom 1 nm to 500 μm, may have a thickness of from 2,000 nm-500,000 nm.

Next, FIG. 3 shows various forms of the phosphor (P) having a core-shellstructure according to some embodiments of the present invention. Across section of the phosphor (P) having a core-shell structureaccording to some embodiments of the present invention may be circularas in the 1st case, polygonal (e.g., triangular, rectangular, andpentagonal) as in the 2nd case, or amorphous as in the 3rd case.

In addition, the phosphor (P) having a core-shell structure according tosome embodiments of the present invention may have various crosssectional forms.

From a three-dimensional view point, the phosphor (P) having acore-shell structure according to some embodiments of the presentinvention may be a sphere, a polyhedron, or an unspecified structure.

Next, FIG. 4 is a view elucidating the use of the phosphor (P) having acore-shell structure according to some embodiments of the presentinvention. The phosphor (P) having a core-shell structure according tosome embodiments of the present invention may find applications in anelectronic apparatus 400 comprising a light-emitting device package 410including at least one light-emitting device, and a driving circuit 420for driving the at least one light emitting device of the light-emittingdevice package 410.

The light emitting device included in the light-emitting device package410 utilizing the phosphor (P) having a core-shell structure accordingto some embodiments of the present invention, may be, for example, anLED (light emitting diode) chip. The light-emitting device package 410can include at least one of one or more phosphors which can be, forexample, the phosphor (P) having the core-shell structure according tothe present invention. A color filter in a display panel of a displayapparatus can include a phosphor (P) that has the core-shell structureaccording to the present invention to enhance the color conversionperformance of the color filter, the phosphor (P) positioned being aboveor below the color filter.

Next, FIG. 5 is a view illustrates three types (e.g., Type 1, Type 2,and Type 3) of a light emitting device packages each utilizing aphosphor (P) having a core-shell structure according to some embodimentsof the present invention. The light-emitting device package 410 (referto FIG. 4) may be of Type 1 inclusive of one kind of light emittingdevices and two kinds of phosphors (refer to FIG. 5).

The light-emitting device package 410 of Type 1 includes, for example,the one kind of light emitting device that may be a blue light emittingdevice emitting blue light while the two kinds of phosphor may becomposed of a red phosphor that emits red light and a green phosphorthat emits green light.

The light-emitting device package 410 of Type 2 or Type 3 can include,for example, two kinds of light emitting devices and one kind ofphosphor (refer to FIG. 5). For the light-emitting device package 410 ofType 2, for example, the two kinds of light emitting devices may becomposed of a blue light emitting device that emits blue light and a redlight emitting device that emits red light while the one kind ofphosphor may be a green phosphor that emits green light. For thelight-emitting device package 410 of Type 3, for example, the two kindsof light emitting devices may be composed of a blue light emittingdevice that emits blue light and a green light emitting device thatemits green light while the one kind of phosphor may be a red phosphorthat emits red light.

Next, FIGS. 6 and 7 are diagrams respectively illustrating, for example,Type 1-a of the three types of the light-emitting device package 410(refer to FIGS. 6, 8, and 10). The light-emitting device package 410 ofType 1-a including one kind of light emitting devices (D1) and two kindsof phosphors (P1 and P2), each having a core-shell structure.

Referring to FIG. 6, the light-emitting device package 410 includes amold 610, one or more first light emitting devices (D1) positioned onthe mold 610, and an encapsulant 620 for encapsulating the first lightemitting devices (D1). The mold 610 and the encapsulant 620 arestructural elements common to all types of the light-emitting devicepackage 410 (refer to FIG. 4). The encapsulant 620 includes a firstphosphor (P1) and a second phosphor (P2).

In Type 1-a of the light-emitting device package 410, each of the firstlight emitting devices (D1) can emit light of a first main wavelengthband within the visible light wavelength band. In Type 1-a of thelight-emitting device package 410, the first phosphor (P1) and thesecond phosphor (P2) each have a core-shell structure.

The first phosphor (P1) may include a first core (PC1) which is composedof a fluorescent material emitting light of a first wavelength banddifferent from the first main wavelength band of the light emitted fromthe first light emitting device (D1), and at least one first shell (PS1)which is applied to the surface of the first core (PC1). The at leastone first shell (PS1) applied to the surface of the first core (PC1)eliminates the light of a first specific wavelength band or attenuatesthe intensity of the light of a first specific wavelength band in thelight of a first wavelength band to emit light of a second mainwavelength band within the visible light wavelength band.

For example, the first light emitting device (D1) may be a blue lightemitting device emitting the first main wavelength band that may be ablue wavelength band of about 380-500 nm.

The first wavelength band of the light that the first core (PC1) of thefirst phosphor (P1) emits may include a green wavelength band that isabout 500-550 nm and may include a G-R mixed color wavelength band,which is about 550-600 nm and ranges from about 500-600 nm.

The first specific wavelength band corresponding to the wavelength bandof the light that is attenuated or eliminated by the first shell (PS1)of the first phosphor (P1) may be, for example, a G-R mixed colorwavelength band that is about 550-600 nm.

The second main wavelength band corresponding to the wavelength band ofthe light that is finally emitted from the first shell (PS1) of thefirst phosphor (P1) may be a green wavelength band that is about 500-550nm. In other words, the green wavelength band that is about 500-550 nmis emitted from the first phosphor (P1).

The first phosphor (P1) having a core-shell structure included in thelight-emitting device package 410 of Type 1-a can emit pure color lightof the second main wavelength band.

To emit pure color light of the second main wavelength band by the firstphosphor (P1), the first shell (PS1) may be a material having a firstlight transmission property of attenuating the intensity of the light ofa first specific wavelength band, corresponding to the wavelength bandof the mixed color light, in the first wavelength band of the lightemitted from the first core (PC1). The intensity of the light of a firstspecific wavelength band is attenuated to less than a thresholdintensity (Sth). The attenuated light is output by the first phosphor(P1) after the incidence of light, to emit pure color light of a secondmain wavelength band.

In the first phosphor (P1), the first core (PC1) may be heavier than thefirst shell (PS1). For example, the weight ratio of the first shell(PS1) to the first core (PC1) in the first phosphor (P1) may be 0.6 orless.

In the first phosphor (P1), the weight ratio of the first shell (PS1) tothe first core (PC1) may be set in such a manner that the intensityattenuation of the light of a first specific wavelength band,corresponding to the wavelength band of the mixed color light, in thefirst wavelength band of the light emitted from the first core (PC1) isa certain level (K) or greater. In other words, the weight ratio of thefirst shell (PS1) to the first core (PC1) in the first phosphor (P1) maybe designed so that the first core (PC1) is heavier than the first shell(PS1) to emit pure color light without degrading luminance performance.

In the first phosphor (P1), the thickness of the first shell (PS1) maybe smaller than the distance (R) from the center (O) of the first core(PC1) to the surface of the first core (PC1). For example, the firstshell (PS1) in the first phosphor (P1) may range in thickness from 1nm-500 μm. More particularly, the first shell (PS1) in the firstphosphor (P1) has a thickness of from 2,000 nm-500,000 nm.

In the first phosphor (P1), the thickness of the first shell (PS1) maybe determined such that the intensity attenuation of the light of afirst specific wavelength band corresponding to the wavelength band ofthe mixed light in the first wavelength band of the light emitted fromthe first core (PC1) is a certain level (K) or greater.

The first phosphor (P1) having a core-shell structure with the thicknessof the first shell (PS1) being smaller than the distance (R) from thecenter (O) of the first core (PC1) to the surface of the first core(PC1) is allowed to emit pure color light without degrading luminanceperformance by designing the thickness of the first shell (PS1).

The first shell (PS1) in the first phosphor (P1) may include at leastone rare earth element from the lanthanum group. As used herein, theterm “rare earth elements from the lanthanum group” refers to seventeenelements including the fifteen lanthanides (atomic numbers 57-71) plusscandium (Sc) and yttrium (Y).

The fifteen lanthanides include La (lanthanum), Ce (cerium), Pr(praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Eu(europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho(holmium), Er (erbium), Tm (thulium), Yb (ytterbium), and Lu (lutetium).

As the first shell (PS1) in the first phosphor (P1) includes at leastone rare earth element from the lanthanum group, as described above, thelight transferred from the first core (PC1) of the first phosphor (P1)can be emitted outside the first shell without loss except the firstspecific wavelength band of the incident light.

In the first phosphor (P1), the first core (PC1) may include, forexample, at least one selected from among (Sr,Ba,Mg)2SiO4:Eu,Al5Lu3O12:Ce, (Sr,Ba,Mg)2SiO4:Eu, Y3Al5O12:Ce, La3Si6N11:Ce,(Sr,Ba,Eu)2SiO4:Eu, β-Sialon:Si6-zAlzOzN8-z:Eu, Lu3Al5O12:Ce, (Lu,Gd)3Al5O12:Ce, and Y3Al5O12:Ce (0.01<z<10).

According to this material, the first core (PC1) of the first phosphor(P1) may absorb light of a blue wavelength band of about 380-500 nmcorresponding to the first main wavelength band of the light emittedfrom the first light emitting device (D1) so as to emit light of a firstwavelength band of about 500-600 nm including a green wavelength band ofabout 500-550 nm and a G-R mixed color wavelength band of about 550-600nm.

With reference to FIGS. 6 and 7, the second phosphor (P2) may include asecond core (PC2) which is composed of a fluorescent material emittinglight of a second wavelength band different from the first mainwavelength band of the light emitted from the first light emittingdevice (D1), and at least one second shell (PS2) (refer to FIGS. 6 and7). The at least one second shell (PS2) is applied to the surface of thesecond core (PC2) and eliminates the light of a second specificwavelength band or attenuates the intensity of the light of a secondspecific wavelength band in the light of a second wavelength band toemit light of a third main wavelength band within the visible lightwavelength band.

Having a core-shell structure with a second core (PC2) composed of afluorescent material emitting light of a second wavelength banddifferent from the first main wavelength band of the light emitted fromthe first light emitting device (D1), the second phosphor (P2) can emitthe pure color light of a third main wavelength band different from boththe first main wavelength band of the pure color light emitted form thefirst light emitting device (D1) and the second main wavelength band ofthe light emitted from the first phosphor (P1).

For example, the first light emitting device (D1) may be a blue lightemitting device, and when the first main wavelength band is a bluewavelength band of about 380-500 nm, the second wavelength band of thelight that the second core (PC2) of the second phosphor (P2) emits mayinclude a red wavelength band of about 600-700 nm and a G-R mixed colorwavelength band of about 550-600 nm, covering a range of about 550-700nm.

The second specific wavelength band which corresponds to the wavelengthband of the light attenuated or eliminated by the second shell (PS2) ofthe second phosphor (P2) may be, for example, a G-R mixed colorwavelength band of about 550-600 nm.

The third main wavelength band which corresponds to the wavelength bandof the light finally emitted from the second shell (PS2) of the secondphosphor (P2), that is, from the second phosphor (P2), may be a redwavelength band of about 600-700 nm.

In the second phosphor (P2), the second shell (PS2) may be a materialhaving a second light transmission property of attenuating the intensityof the light of a second specific wavelength band, corresponding to thewavelength band of the mixed color light, in the second wavelength bandof the light emitted from the second core (PC2) to less than a thresholdintensity (Sth) and outputting the attenuated light after the incidenceof light.

Accordingly, the second phosphor (P2) may emit pure color light of athird main wavelength band by reducing the intensity of the light of thesecond specific wavelength band corresponding to the mixed colorwavelength band.

In the second phosphor (P2), the second core (PC2) may be heavier thanthe second shell (PS2).

For example, the weight ratio of the second shell (PS2) to the secondcore (PC2) in the second phosphor (P2) may be 0.6 or less.

In the second phosphor (P2), the weight ratio of the second shell (PS2)to the second core (PC2) may be set in such a manner that the intensityattenuation of the light of a second specific wavelength band,corresponding to the wavelength band of the mixed color light, in thesecond wavelength band of the light emitted from the second core (PC2)is a certain level (K) or greater.

In a second phosphor (P2) having a core-shell structure, as mentionedabove, a weight ratio of a second shell (PS2) to a second core (PC2) maybe designed so as to emit pure color light without degrading luminanceperformance.

In the second phosphor (P2), the thickness of the second shell (PS2) maybe smaller than the distance (R) from the center (O) of the second core(PC2) to the surface of the second core (PC2). For example, the secondshell (PS2) in the second phosphor (P2) may range in thickness from 1nm-500 μm.

More particularly, the second shell (PS2) in the second phosphor (P2)has a thickness of from 2,000 nm-500,000 nm.

In the second phosphor (P2), the thickness of the second shell (PS2) maybe determined such that the intensity attenuation of the light of asecond specific wavelength band corresponding to the wavelength band ofthe mixed light in the second wavelength band of the light emitted fromthe second core (PC2) is a certain level (K) or greater.

The second phosphor (P2) having a core-shell structure with thethickness of the second shell (PS2) being smaller than the distance (R)from the center (O) of the second core (PC2) to the surface of thesecond core (PC2) is allowed to emit pure color light without degradingluminance performance by designing the thickness of the second shell(PS2).

The second shell (PS2) in the second phosphor (P2) may include at leastone rare earth element from the lanthanum group. As used herein, theterm “rare earth elements from the lanthanum group” refers to seventeenelements including the fifteen lanthanides (atomic numbers 57-71) plusscandium (Sc) and yttrium (Y).

The fifteen lanthanides include La (lanthanum), Ce (cerium), Pr(praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Eu(europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho(holmium), Er (erbium), Tm (thulium), Yb (ytterbium), and Lu (lutetium).

As the second shell (PS2) in the second phosphor (P2) includes at leastone rare earth element from the lanthanum group, and as described above,the light transferred from the second core (PC2) of the second phosphor(P2) can be emitted outside the second shell without loss except thesecond specific wavelength band of the incident light.

In the second phosphor (P2), the second core (PC2) may include, forexample, at least one selected from among (Sr,Ba,Mg)3SiO5:Eu,(Sr,Ca)AlSiN3:Eu, CaAlSiN3:Eu, MyM′z(Si,B,Al)5OxN8-x:Eu,MSil-zAlzOzN2-z:Eu, α-Sialon:CaxEuy(Si,Al)12(O,N)16, and S—CaAlSiN,CaAlSiN, (Sr,Ca)AlSiN3:Eu, K2SiF6:Mn4+ (0.01<x<10, 0.01<y<20, 0.01<z<10,M and M′ may each be selected from among Ca, Sr, and Ba).

According to this material, the second core (PC2) of the second phosphor(P2) may absorb light of a blue wavelength band of about 380-500 nmcorresponding to the first main wavelength band of the light emittedfrom the first light emitting device (D1) so as to emit light of asecond wavelength band of about 550-700 nm including a red wavelengthband of about 600-700 nm and a G-R mixed color wavelength band of about550-600 nm.

In the light-emitting device package 410 of Type 1-a, the first specificwavelength band, which is the wavelength band of the light eliminated orattenuated by the first shell (PS1) of the first phosphor (P1) may beidentical to or overlap with the second specific wavelength band, whichis the wavelength band of the light eliminated or attenuated by thesecond shell (PS2) of the second phosphor (P2).

In the light-emitting device package 410 of Type 1-a, if necessary, thefirst specific wavelength band, which is the wavelength band of thelight eliminated or attenuated by the first shell (PS1) of the firstphosphor (P1) may be different from the second specific wavelength band,which is the wavelength band of the light eliminated or attenuated bythe second shell (PS2) of the second phosphor (P2), without overlaptherebetween.

As indicated by the design for a wavelength band to be attenuated oreliminated, the light transmission properties in each of the first shell(PS1) of the first phosphor (P1) and the second shell (PS2) of thesecond phosphor (P2) can be controlled depending on the presence orabsence of a B-G mixed color wavelength band between a blue wavelengthband and a green wavelength band and a G-R mixed color wavelength bandbetween a green wavelength band and a red wavelength band, and a degreeof color mixing. Through the control, improvement can be made of entirecolor reproduction capability in the light-emitting device package 410.

The weight ratio of the first shell (PS1) to the first core (PC1) in thefirst phosphor (P1) may be identical to or different from that of thesecond shell (PS2) to the second core (PS2) in the second phosphor (P2).

As indicated by the aforementioned design for the weight ratio, thelight transmission properties in each of the first shell (PS1) of thefirst phosphor (P1) and the second shell (PS2) of the second phosphor(P2) can be controlled depending on the presence or absence of a B-Gmixed color wavelength band between a blue wavelength band and a greenwavelength band, and a G-R mixed color wavelength band between a greenwavelength band and a red wavelength band, and a degree of color mixing.Through the control, improvement can be made of entire colorreproduction capability in the light-emitting device package 410.

The thickness of the first shell (PS1) in the first phosphor (P1) may beidentical to or different from that of the second shell (PS2) in thesecond phosphor (P2).

As indicated by the design for the shell thicknesses, the lighttransmission properties in each of the first shell (PS1) of the firstphosphor (P1) and the second shell (PS2) of the second phosphor (P2) canbe controlled depending on the presence or absence of a B-G mixed colorwavelength band between a blue wavelength band and a green wavelengthband, and a G-R mixed color wavelength band between a green wavelengthband and a red wavelength band, and a degree of color mixing. Throughthe control, improvement can be made of entire color reproductioncapability in the light-emitting device package 410.

In a case where a mixed color wavelength band relating to the secondwavelength band of the light emitted from the second core (PC2) of thesecond phosphor (P2) has greater influence on pure color reproduction,the second shell (PS2) of the second phosphor (P1) may be designed to bethicker than the first shell (PS1) of the first phosphor (P1), forexample.

When a mixed color wavelength band relating to the second wavelengthband of the light emitted from the second core (PC2) of the secondphosphor (P2) has greater influence on pure color reproduction, suchdesigning makes it possible to more effectively eliminate the light ofthe second specific wavelength from the light emitted from the secondcore (PC2) of the second phosphor (P2), thereby improving pure colorreproduction capability in the light-emitting device package 410.

Next, FIGS. 8 and 9 are diagrams respectively showing a light-emittingdevice package of Type 1-b including one kind of light emitting device(e.g., blue light emitting device) and two kinds of phosphors (greenphosphors (P1) and red phosphors (P2)), and a green phosphor (P1) havinga core-shell structure and a red phosphor (P2) having a structureaccording to the present application.

The light-emitting device package 410 of Type 1-b may comprise a firstlight emitting device (D1) emitting the light of a first main wavelengthband within the visible wavelength band.

The light-emitting device package 410 of Type 1-b may comprise a firstphosphor (P1) and a second phosphor (P2).

The first phosphor (P1) may have a core-shell structure.

The second phosphor (P2) has a structure according to related artconsisting of a core alone, without shells. That is, the second phosphor(P2) does not have a core-shell structure.

The first phosphor (P1) may include a first core (PC1) which is composedof a fluorescent material emitting light of a first wavelength banddifferent from the first main wavelength band of the light emitted fromthe first light emitting device (D1), and at least one first shell (PS1)which is applied to the surface of the first core (PC1) and whicheliminates the light of a first specific wavelength band or attenuatesthe intensity of the light of a first specific wavelength band in thelight of a first wavelength band to emit light of a second mainwavelength band within the visible light wavelength band.

For example, the first light emitting device (D1) may be a blue lightemitting device and the first main wavelength band may be a bluewavelength band of about 380-500 nm.

The first wavelength band of the light that the first core (PC1) in thefirst phosphor (P1) emits may include a green wavelength band of about500-550 nm and a G-R mixed color wavelength band, which is about 550-600nm and covers a range from about 500-600 nm.

The first specific wavelength band corresponding to the wavelength bandof the light that is attenuated or eliminated by the first shell (PS1)of the first phosphor (P1) may be, for example, a G-R mixed colorwavelength band of about 550-600 nm.

The second main wavelength band corresponding to the wavelength band ofthe light that is finally emitted from the first shell (PS1) of thefirst phosphor (P1), that is, from the first phosphor (P1) may be agreen wavelength band of about 500-550 nm.

Having a core-shell structure, as described above, the first phosphor(P1) can emit pure color light of the second main wavelength band.

In the first phosphor (P1), the first shell (PS1) may be a materialhaving a first light transmission property of attenuating the intensityof the light of a first specific wavelength band, corresponding to thewavelength band of the mixed color light, in the first wavelength bandof the light emitted from the first core (PC1) to less than a thresholdintensity (Sth) and outputting the attenuated light after the incidenceof light.

Accordingly, the first phosphor (P1) may emit pure color light of asecond main wavelength band by reducing the intensity of the light ofthe first specific wavelength band corresponding to the mixed colorwavelength band.

In the first phosphor (P1), the weight ratio of the first shell (PS1) tothe first core (PC1) may be 0.6 or less. In order words, the weight ofthe shell (PS1) may be set to be 0.6 or less in the first phosphor (P1)when the weight of the first core (PC1) is 1.

In the first phosphor (P1), the weight ratio of the first shell (PS1) tothe first core (PC1) may be set in such a manner that the intensityattenuation of the light of a first specific wavelength band,corresponding to the wavelength band of the mixed color light, in thefirst wavelength band of the light emitted from the first core (PC1) isa certain level (K) or greater.

In a first phosphor (P1) having a core-shell structure, as mentionedabove, a weight ratio of a first shell (PS1) to a first core (PC1) maybe designed so as to emit pure color light without degrading luminanceperformance.

In the first phosphor (P1), the first shell (PS1) may range in thicknessfrom 1 nm-500 μm.

More particularly, the first shell (PS1) in the first phosphor (P1) hasa thickness of from 2,000 nm-500,000 nm.

In the first phosphor (P1), the thickness of the first shell (PS1) maybe determined such that the intensity attenuation of the light of afirst specific wavelength band corresponding to the wavelength band ofthe mixed color light in the first wavelength band of the light emittedfrom the first core (PC1) is a certain level (K) or greater.

As described above, designing the thickness of the first shell (PS1) inthe first phosphor (P1) having a core-shell structure, that is,designing the thickness of the first shell (PS1) wrapping the first core(PC1) in consideration of the size of the first core (PC1) allows theemission of pure color light without degrading luminance performance.

The first shell (PS1) in the first phosphor (P1) may include at leastone rare earth element from the lanthanum group.

As used herein, the term “rare earth elements from the lanthanum group”refers to seventeen elements including the fifteen lanthanides (atomicnumbers 57-71) plus scandium (Sc) and yttrium (Y).

The fifteen lanthanides include La (lanthanum), Ce (cerium), Pr(praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Eu(europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho(holmium), Er (erbium), Tm (thulium), Yb (ytterbium), and Lu (lutetium).

As the first shell (PS1) in the first phosphor (P1) includes at leastone rare earth element from the lanthanum group, as described above, thelight transferred from the first core (PC1) of the first phosphor (P1)can be emitted outside the first shell without loss except the firstspecific wavelength band of the incident light.

In the first phosphor (P1), the first core (PC1) may include, forexample, at least one selected from among (Sr,Ba,Mg)2SiO4:Eu,Al5Lu3O12:Ce, (Sr,Ba,Mg)2SiO4:Eu, Y3Al5O12:Ce, La3Si6N11:Ce,(Sr,Ba,Eu)2SiO4:Eu, β-Sialon:Si6-zAlzOzN8-z:Eu, Lu3Al5O12:Ce, (Lu,Gd)3Al5O12:Ce, and Y3Al5O12:Ce (0.01<z<10).

According to this material, the first core (PC1) of the first phosphor(P1) may absorb light of a blue wavelength band of about 380-500 nmcorresponding to the first main wavelength band of the light emittedfrom the first light emitting device (D1) so as to emit light of a firstwavelength band of about 500-600 nm including a green wavelength band ofabout 500-550 nm and a G-R mixed color wavelength band of about 550-600nm.

With reference to FIGS. 8 and 9, the second phosphor (P2) may include asecond core (PC2) which is composed of a fluorescent material emittinglight of a second wavelength band different from the first mainwavelength band of the light emitted from the first light emittingdevice (D1), but a shell applied to the surface of the second core (PC2)does not exist.

The second core (PC2) in the second phosphor (P2) may emit light of asecond wavelength band covering a red wavelength band alone or plus aG-R mixed color wavelength band.

A G-R mixed color wavelength, although existing in the light emittedfrom the second core (PC2) of the second phosphor (P2), can be reducedor eliminated by the first shell (PS1) of the first phosphor (P1).

Of the two phosphors (P1 and P2), as described above, only the firstphosphor (P1), which corresponds to a green phosphor, is of a core-shellstructure while the second phosphor (P2), which corresponds to a redphosphor, has a structure according to related art including a corealone. If the light-emitting device package 410 improves in entire purecolor reproduction capability, it unnecessary to make both phosphors (P1and P2) have a core-shell structure. In this regard the production costand process complexity of the phosphor can be reduced.

Next, FIGS. 10 and 11 are diagrams respectively showing a light-emittingdevice package of Type 1-c including one kind of light emitting device(blue light emitting device) and two kinds of phosphors (red phosphors(P1) and green phosphors (P2)), and a red phosphor (P1) having acore-shell structure and a green phosphor (P2) having a structureaccording to the present application.

The light-emitting device package 410 of Type 1-c may comprise a firstlight emitting device (D1) emitting the light of a first main wavelengthband within the visible wavelength band.

The light-emitting device package 410 of Type 1-c may comprise a firstphosphor (P1) and a second phosphor (P2).

The first phosphor (P1) may have a core-shell structure.

The second phosphor (P2) has a structure according to related artconsisting of a core alone, without shells. That is, the second phosphor(P2) does not have a core-shell structure.

The first phosphor (P1) may include a first core (PC1) which is composedof a fluorescent material emitting the light of a first wavelength banddifferent from the first main wavelength band of the light emitted fromthe first light emitting device (D1), and at least one first shell (PS1)which is applied to the surface of the first core (PC1) and whicheliminates the light of a first specific wavelength band or attenuatesthe intensity of the light of a first specific wavelength band in thelight of a first wavelength band to emit the light of a second mainwavelength band within the visible light wavelength band.

For example, the first light emitting device (D1) may be a blue lightemitting device and the first main wavelength band may be a bluewavelength band of about 380-500 nm.

The first wavelength band of the light emitted by the first core (PC1)in the first phosphor (P1), which is a red phosphor, may include a redwavelength band about 600-700 nm and a G-R mixed color wavelength band,which is about 550-600 nm and covers a range of from about 550-700 nm.

The first specific wavelength band corresponding to the wavelength bandof the light that is attenuated or eliminated by the first shell (PS1)of the first phosphor (P1) may be, for example, a G-R mixed colorwavelength band about 600-700 nm.

The second main wavelength band corresponding to the wavelength band ofthe light that is finally emitted from the first shell (PS1) of thefirst phosphor (P1), that is, from the first phosphor (P1) may be a redwavelength band of about 600-700 nm.

Having a core-shell structure, as described above, the first phosphor(P1) can emit pure color light of the second main wavelength band.

In the first phosphor (P1), the first shell (PS1) may be a materialhaving a first light transmission property of attenuating the intensityof the light of a first specific wavelength band, corresponding to thewavelength band of the mixed color light, in the first wavelength bandof the light emitted from the first core (PC1) to less than a thresholdintensity (Sth) and outputting the attenuated light after the incidenceof light. Accordingly, the first phosphor (P1) may emit pure color lightof a second main wavelength band.

In the first phosphor (P1), the weight ratio of the first shell (PS1) tothe first core (PC1) may be 0.6 or less. In the first phosphor (P1), theweight ratio of the first shell (PS1) to the first core (PC1) may be setin such a manner that the intensity attenuation of the light of a firstspecific wavelength band, corresponding to the wavelength band of themixed color light, in the first wavelength band of the light emittedfrom the first core (PC1) is a certain level (K) or greater.

In a first phosphor (P1) having a core-shell structure, as mentionedabove, a weight ratio of a first shell (PS1) to a first core (PC1) maybe designed so as to emit pure color light without degrading luminanceperformance.

In the first phosphor (P1), the first shell (PS1) may range in thicknessfrom 1 nm-500 μm.

More particularly, the first shell (PS1) in the first phosphor (P1) hasa thickness of from 2,000 nm-500,000 nm.

In the first phosphor (P1), the thickness of the first shell (PS1) maybe determined such that the intensity attenuation of the light of afirst specific wavelength band corresponding to the wavelength band ofthe mixed color light in the first wavelength band of the light emittedfrom the first core (PC1) is a certain level (K) or greater. The firstshell (PS1) that is included in the first phosphor (P1) with acore-shell structure has the thickness wrapping the first core (PC1) toallow the emission of pure color light without degrading luminanceperformance.

The first shell (PS1) in the first phosphor (P1) may include at leastone rare earth element from the lanthanum group.

As used herein, the term “rare earth elements from the lanthanum group”refers to seventeen elements including the fifteen lanthanides (atomicnumbers 57-71) plus scandium (Sc) and yttrium (Y).

The fifteen lanthanides include La (lanthanum), Ce (cerium), Pr(praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Eu(europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho(holmium), Er (erbium), Tm (thulium), Yb (ytterbium), and Lu (lutetium).

As the first shell (PS1) in the first phosphor (P1) includes at leastone rare earth element from the lanthanum group, as described above, thelight transferred from the first core (PC1) of the first phosphor (P1)can be emitted outside the first shell without loss except the firstspecific wavelength band of the incident light.

In the first phosphor (P1), the first core (PC1) may include, forexample, at least one selected from among (Sr,Ba,Mg)2SiO4:Eu,Al5Lu3O12:Ce, (Sr,Ba,Mg)2SiO4:Eu, Y3Al5O12:Ce, La3Si6N11:Ce,(Sr,Ba,Eu)2SiO4:Eu, β-Sialon:Si6-zAlzOzN8-z:Eu, Lu3Al5O12:Ce, (Lu,Gd)3Al5O12:Ce, and Y3Al5O12:Ce (0.01<z<10).

According to this material, the first core (PC1) of the first phosphor(P1) may absorb light of a blue wavelength band of about 380-500 nmcorresponding to the first main wavelength band of the light emittedfrom the first light emitting device (D1) so as to emit light of a firstwavelength band of about 500-600 nm including a green wavelength band ofabout 500-550 nm and a G-R mixed color wavelength band of about 550-600nm.

The second phosphor (P2) may include a second core (PC2) which iscomposed of a fluorescent material emitting light of a second wavelengthband different from the first main wavelength band of the light emittedfrom the first light emitting device (D1), but a shell wrapping thesecond core (PC2) does not exist.

The second core (PC2) in the second phosphor (P2) may emit light of asecond wavelength band covering a green wavelength band alone or plus aG-R (B-G) mixed color wavelength band.

A G-R mixed color wavelength, although existing in the light emittedfrom the second core (PC2) of the second phosphor (P2), can be reducedor eliminated by the first shell (PS1) of the first phosphor (P1).

Of the two phosphors (P1 and P2), as described above, only the firstphosphor (P1), which corresponds to a red phosphor, is of a core-shellstructure while the second phosphor (P2), which corresponds to a greenphosphor, has a general structure. If the light-emitting device package410 improves in entire pure color reproduction capability, it isunnecessary to make both phosphors (P1 and P2) have a core-shellstructure. In this regard the production cost and process complexity ofthe phosphor can be reduced.

Next, FIGS. 12 and 13 are diagrams respectively showing a light-emittingdevice package of Type 2 including two kinds of light emitting devices(blue light emitting device and red light emitting device) and one kindof phosphors (e.g., a green phosphor), and a green phosphor having acore-shell structure.

The light-emitting device package 410 may comprise a first lightemitting device (D1) and a second light emitting device (D2) which emitthe light of a first main wavelength band (blue wavelength band) and athird main wavelength band (e.g., a red wavelength band), respectively,within the visible light wavelength band.

For example, the first light emitting device (D1) may be a blue lightemitting device and the first main wavelength band may be a bluewavelength band of about 380-500 nm. The second light emitting device(D2) may be a red light emitting device, and the third main wavelengthband may be a red wavelength band of about 600-700 nm.

The light-emitting device package 410 of Type 2 may include a firstphosphor (P1), corresponding to a green phosphor, having a core-shellstructure.

The first phosphor (P1) may include a first core (PC1) which is composedof a fluorescent material emitting the light of a first wavelength banddifferent from the first main wavelength band of the light emitted fromthe first light emitting device (D1), and at least one first shell (PS1)which is applied to the surface of the first core (PC1) and whicheliminates the light of a first specific wavelength band or attenuatethe intensity of the light of a first specific wavelength band in thelight of a first wavelength band to emit light of a second mainwavelength band within the visible light wavelength band.

For example, the first wavelength band of the light that the first core(PC1) of the first phosphor (P1) emits may include a green wavelengthband of about 500-550 nm and a G-R mixed color wavelength band, which isabout 550-600 nm and covers a range from about 500-600 nm.

The first specific wavelength band corresponding to the wavelength bandof the light that is attenuated or eliminated by the first shell (PS1)of the first phosphor (P1) may be, for example, a G-R mixed colorwavelength band of about 550-600 nm.

The second main wavelength band corresponding to the wavelength band ofthe light that is finally emitted from the first shell (PS1) of thefirst phosphor (P1), that is, from the first phosphor (P1) may be agreen wavelength band of about 500-550 nm.

In another embodiment, the first wavelength band of the light emitted bythe first core (PC1) of the first phosphor (P1) may include a greenwavelength band of about 500-550 nm and a B-G mixed color wavelengthband of about 480-500 nm, covering a range of about 480-550 nm.

The first specific wavelength band corresponding to the wavelength bandof the light attenuated or eliminated by the first shell (PS1) of thefirst phosphor (P1) may be a B-G mixed color wavelength band of about480-500 nm.

The second main wavelength band corresponding to the wavelength band ofthe light finally emitted from the first shell (PS1) of the firstphosphor (P1), that is, from the first phosphor (P1), may be a greenwavelength band of about 500-550 nm. Two colors (e.g., blue and red) outof three colors (e.g., red, green, and blue) may be expressed by purecolor light using the two light emitting devices (D1 and D2) while theother color (e.g., green) may be expressed by pure color light using thefirst phosphor (P1) having a core-shell structure.

Next, FIGS. 14 and 15 are diagrams respectively showing a light-emittingdevice package of Type 3 including two kinds of light emitting devices(e.g., a blue light emitting device and a green light emitting device)and one kind of phosphor (e.g., a red phosphor), having a core-shellstructure.

The light-emitting device package 410 of Type 3 may comprise a firstlight emitting device (D1) and a second light emitting device (D2) whichemit the light of a first main wavelength band (blue wavelength band)and a third main wavelength band (e.g., a green wavelength band),respectively, within the visible light wavelength band.

For example, the first light emitting device (D1) may be a blue lightemitting device and the first main wavelength band may be a bluewavelength band of about 380-500 nm. The second light emitting device(D2) may be a green light emitting device, and the third main wavelengthband may be a green wavelength band of about 500-550 nm.

The light-emitting device package 410 of Type 3 may include a firstphosphor (P1), corresponding to a red phosphor, having a core-shellstructure. The first phosphor (P1) may include a first core (PC1) whichis composed of a fluorescent material emitting the light of a firstwavelength band different from the first main wavelength band of thelight emitted from the first light emitting device (D1), and at leastone first shell (PS1) which is applied to the surface of the first core(PC1) and which eliminates the light of a first specific wavelength bandor attenuates the intensity of the light of a first specific wavelengthband in the light of a first wavelength band to emit light of a secondmain wavelength band within the visible light wavelength band.

For example, the first wavelength band of the light that the first core(PC1) of the first phosphor (P1), which is a red phosphor, emits mayinclude a red wavelength band of about 600-700 nm and a G-R mixed colorwavelength band of about 550-600 nm, covering a range of from about550-700 nm.

The first specific wavelength band corresponding to the wavelength bandof the light that is attenuated or eliminated by the first shell (PS1)of the first phosphor (P1) may be, for example, a G-R mixed colorwavelength band of about 550-600 nm.

The second main wavelength band corresponding to the wavelength band ofthe light that is finally emitted from the first shell (PS1) of thefirst phosphor (P1), may be a red wavelength band of about 600-700 nm.

Two colors (e.g., blue and green), of red, green, and blue colors, maybe expressed as pure color light using the two light emitting devices(D1 and D2) while the other color (e.g., red) may be expressed as purecolor light using the first phosphor (P1) having a core-shell structure.

Next, FIG. 16 shows emission spectra of the light-emitting devicepackage 410 in which the gamut of pure colors is improved as thecore-shell structure of the green phosphor eliminates a G-R mixed colornoise in accordance with some embodiments of the present invention.

In the case of the light emitting device packages 410 of Types 1-a and1-b (e.g., white light emitting device packages using blue lightemitting devices, and red and green phosphors), a comparison is made ofemission spectra between a light emitting device package in which thegreen phosphor has a structure according to related art lacking a shelland a light emitting device package 410 according to some embodiments ofthe present invention in which the green phosphor has a core-shellstructure provided with a shell (refer to FIG. 16).

For a green phosphor having a structure according to related artconsisting of a core without a shell, the emission spectrum shows themixing of green and red colors because the intensity of the light in thegreen-red (G-R) mixed color wavelength band (NP) is similar to theintensity of the light in the pure green wavelength band and in the purered wavelength band, without a significant difference therebetween.

As a result of the intensity of the light in the G-R mixed colorwavelength band (NP) being similar to the intensity of the light in thepure green wavelength band and in the pure red wavelength band, thelight-emitting device package according to related art has a problem inthat it cannot reproduce pure colors with a decrease in the emissionperformance of white light. A display apparatus or illuminationapparatus employing the light-emitting device package according torelated art has inferior color reproduction capability.

For a green phosphor having a core-shell structure provided with a shellaccording to the light-emitting device package of the presentapplication, the shell of the green phosphor absorbs the light of a G-Rmixed color wavelength band (NP) from the light emitted by the core ofthe green phosphor to emit pure or substantially pure green color lightthat is completely or mostly free of the light of the G-R mixed colorwavelength band (NP).

As can be seen in the emission spectrum of the green phosphor having acore-shell structure provided with a shell, the intensity of light in aG-R mixed color wavelength band (NP) is greatly lower than light in apure green wavelength band and in a pure red green wavelength band, sothat the mixing of green and red colors is completely or substantiallyremoved.

As a result, the light-emitting device package 410 according to someembodiments of the present invention can reproduce pure colors with theconsequent increase of the emission performance of white light. Anelectronic apparatus 400, such as a display apparatus or illuminationapparatus employing the light-emitting device package 410, may greatlyimprove in color reproduction capability.

Meanwhile, a higher content of the green phosphors having a core-shellstructure in the encapsulant 620 allows the light finally emitted by thegreen phosphors to appear at a higher intensity in the emissionspectrum, thereby further increasing the gamut of pure colors.

Next, FIG. 17 shows emission spectra of the light-emitting devicepackage 410 in which the gamut of pure colors is improved as thecore-shell structure of the red phosphor eliminates a G-R mixed colornoise in accordance with some embodiments of the present invention.

In the case of the light emitting device packages 410 of Types 1-a and1-c (e.g., white light emitting device packages using blue lightemitting devices, and red and green phosphors), a comparison is made ofemission spectra between a light emitting device package in which thered phosphor has a structure according to related art lacking a shelland a light emitting device package 410 according to some embodiments ofthe present invention in which the red phosphor has a core-shellstructure provided with a shell (refer to FIG. 17).

For a red phosphor having a structure according to related artconsisting of a core without a shell, the emission spectrum shows themixing of green and red colors because the intensity of the light in theG-R mixed color wavelength band (NP) is similar to those of the light inthe pure green wavelength band and in the pure red wavelength band,without a significant difference therebetween.

As a result, the light-emitting device package according to related artcannot reproduce pure colors with a decrease in the emission performanceof white light. A display apparatus or illumination apparatus employingthe light-emitting device package according to related art may havegreatly decreased color reproduction capability.

For a red phosphor having a core-shell structure provided with a shell,in contrast, the shell of the red phosphor absorbs the light of a G-Rmixed color wavelength band (NP) from the light emitted by the core ofthe red phosphor to emit pure or substantially pure red color light thatis free of or reduced in the light of a G-R mixed color wavelength band(NP).

As can be seen in the emission spectrum of the red phosphor having acore-shell structure provided with a shell, the intensity of light inthe G-R mixed color wavelength band (NP) is greatly lower than light ina pure green wavelength band and in a pure red green wavelength band, sothat the mixing of green and red colors is completely or substantiallyremoved.

As a result, the light-emitting device package 410 according to someembodiments of the present invention can reproduce pure colors with theconsequent increase of the emission performance of white light. Anelectronic apparatus 400, such as a display apparatus or illuminationapparatus employing the light-emitting device package 410, may havegreatly improved color reproduction capability.

Meanwhile, a higher content of the red phosphors having a core-shellstructure in the encapsulant 620 allows the light finally emitted by thered phosphors to appear at a higher intensity in the emission spectrum,thereby further increasing the gamut of pure colors.

Next, FIG. 18 shows emission spectra of the light-emitting devicepackage in which the gamut of pure colors is improved as the core-shellstructure of the green phosphor eliminates a B-G mixed color noise inaccordance with some embodiments of the present invention.

In the case of the light emitting device packages 410 of Types 1-a and1-b (that is, white light emitting device packages using blue lightemitting devices, and red and green phosphors), comparison is made ofemission spectra between a light emitting device package in which thegreen phosphor has a structure according to related art lacking a shelland a light emitting device package 410 according to some embodiments ofthe present invention in which the green phosphor has a core-shellstructure provided with a shell, with reference to FIG. 18.

For a green phosphor having a structure according to related artconsisting of a core without a shell, the emission spectrum shows themixing of blue and green colors because the intensity of the light inthe blue-green (B-G) mixed color wavelength band (NP) is similar tothose of the light in the pure green wavelength band and in the pureblue wavelength band, without a significant difference therebetween.

As a result, the light-emitting device package according to related artcannot reproduce pure colors with a decrease in the emission performanceof white light. A display apparatus or illumination apparatus employingthe light-emitting device package according to related art may havegreatly decreased color reproduction capability.

For a green phosphor having a core-shell structure provided with ashell, in contrast, the shell of the green phosphor absorbs the light ofa B-G mixed color wavelength band (NP) from the light emitted by thecore of the green phosphor to emit pure or substantially pure greencolor light that is free of or reduced in the light of a B-G mixed colorwavelength band (NP).

As can be seen in the emission spectrum of the green phosphor having acore-shell structure provided with a shell, the intensity of light in aB-G mixed color wavelength band (NP) is greatly lower than light in apure green wavelength band and in a pure blue wavelength band, so thatthe mixing of green and blue colors is completely or substantiallyremoved.

As a result, the light-emitting device package 410 according to someembodiments of the present invention can reproduce pure colors with theconsequent increase of the emission performance of white light. Anelectronic apparatus 400, such as a display apparatus or illuminationapparatus employing the light-emitting device package 410, may havegreatly improved color reproduction capability.

Meanwhile, a higher content of the green phosphors having a core-shellstructure in the encapsulant 620 allows the light finally emitted by thegreen phosphors to appear at a higher intensity in the emissionspectrum, thereby further increasing the gamut of pure colors.

As stated hitherto, the phosphor (P) having a core-shell structure canbe applied to the light-emitting device package 410.

The light-emitting device package 410 may be used as a light source inan electronic apparatus, such as a display apparatus and an illuminationapparatus.

Further, the phosphor (P) having a core-shell structure may findapplications in supplementary color coversion layers for enhancing thecolor conversion performance of color filters.

Hereinafter, an electronic apparatus taking advantage of the lightemitting device package 410 including a phosphor (P) having a core-shellstructure according to some embodiments of the present invention will bedescribed.

Next, FIGS. 19 and 20 are schematic views illustrating a displayapparatus 1900 including two types of a backlight units 1910 thatutilize a light-emitting device package 410 comprising a phosphor (P)having a core-shell structure according to some embodiments of thepresent invention, and FIG. 21 is a schematic view illustrating anillumination apparatus 2100 that utilizes a light-emitting devicepackage 410 comprising a phosphor (P) having a core-shell structureaccording to some embodiments of the present invention. An electronicapparatus 400, such as a display apparatus 1900 and an illuminationapparatus 2100 in accordance with some embodiments of the presentinvention, may include one or more light-emitting device packages 410,and one or more driving circuits 420, included in the light-emittingdevice packages 410, for operating light emitting devices (refer toFIGS. 19-21).

Each light-emitting device package 410 may include a first lightemitting device emitting the light of a first main wavelength band(e.g., a blue wavelength band) within the visible light wavelength band,and a first phosphor emitting the light of a second main wavelength banddifferent from the first main wavelength band.

The first phosphor may comprise a first core composed of a fluorescentmaterial for emitting the light of a first wavelength band (e.g., awavelength band including a green wavelength band and a green-red (G-R)mixed color wavelength band, a red wavelength band and a G-R mixed colorwavelength band, or a green wavelength band and a B-G mixed colorwavelength band) different from the first main wavelength band of thelight emitted from the first light emitting device, and at least onefirst shell, applied to the surface of the first core, for emitting thelight of a second main wavelength band (e.g., a green wavelength band ora red wavelength band) within the visible light wavelength band byeliminating the light of a first specific wavelength band (e.g., agreen-red (G-R) mixed color wavelength band or a B-G mixed colorwavelength band) or by attenuating the intensity of light of a firstspecific wavelength band from the light of the first wavelength band.

Utilizing as a light source the light emitting device package 410including a phosphor having a core-shell structure, as stated above, theelectronic apparatus 400, such as the display apparatus 1900 or theillumination apparatus 2100, can exhibit greatly improved colorreproduction capability.

A light-emitting device package 410 including a phosphor having acore-shell structure may be positioned under a display panel 1920 toserve as a white light source for providing white light for the displaypanel 1920 (refer to FIG. 19). In other words, a direct-typelight-emitting device package 410 including a phosphor having acore-shell structure may be used as a light source for a backlight unit110. A light-emitting device package 410 including a phosphor having acore-shell structure may be used as a light source installed in anedge-type backlight unit 1910 including a light guide plate 1911positioned under a display panel 1920 (refer to FIG. 20).

For an edge-type backlight unit 1910, the light-emitting device package410 including a phosphor having a core-shell structure may be located atan edge portion of a display panel 1920.

The edge-type backlight unit 1910 may further comprise a reflector 1912positioned under the light guide plate 1911.

Meanwhile, the phosphor P having a core-shell structure according tosome embodiments of the present invention may serve to supplement thecolor conversion performance of a color filter.

Next, FIG. 22 is a view illustrating a display apparatus 1900 furtherincluding a supplementary color conversion layer 2210 that utilizesphosphors (Pr, Pg, and Pb) in a core-shell structure according to someembodiments of the present invention. Phosphors (Pr, Pg, and Pb), eachhaving a core-shell structure, according to some embodiment of thepresent invention may be contained in supplementary color conversionlayers 2210 that are located beneath or on corresponding color filters(CFr, CFg, and CFb) so as to supplement the color conversion performanceof the color filters (CFr, CFg, CFb).

A black matrix (BM) may be interposed between color filters (CFr, CFg,and CFb) and the supplementary color conversion layer 2210 may becomposed of an encapsulant and the like containing the phosphors (Pr,Pg, and Pb) therein.

Located under or over a red color filter (CFr) may be a red phosphor(Pr) comprising a core which emits the light of a wavelength bandincluding a red wavelength band and a mixed color wavelength band, and ashell which wraps the core and emits the light of a pure red wavelengthband by removing the light of the mixed color wavelength band or byattenuating the intensity of the light of the mixed color wavelengthband from the light emitted by the core.

Located under or over a green color filter (CFg) may be a green phosphor(Pg) comprising a core which emits the light of a wavelength bandincluding a green wavelength band and a mixed color wavelength band, anda shell which wraps the core and emits the light of a pure greenwavelength band by removing the light of the mixed color wavelength bandor by attenuating the intensity of the light of the mixed colorwavelength band from the light emitted by the core.

Located under or over a blue color filter (CFb) may be a blue phosphor(Pb) comprising a core which emits the light of a wavelength bandincluding a blue wavelength band and a mixed color wavelength band, anda shell which wraps the core and emits the light of a pure bluewavelength band by removing the light of the mixed color wavelength bandor by attenuating the intensity of the light of the mixed colorwavelength band from the light emitted by the core.

Under or over all of the red color filter (CFr), the green color filter(CFg), and the blue color filter (CFb), corresponding color phosphorsmay exit. Alternatively, corresponding color phosphors may be positionedunder or over one or two of the red color filter (CFr), the green colorfilter (CFg), and the blue color filter (CFb).

As elucidated hitherto, a phosphor that has a core-shell structure andexhibits an excellent gamut of pure colors is provided in accordancewith some embodiments of the present invention.

A light-emitting device package 410 including a phosphor having acore-shell structure is provided in accordance with some embodiments ofthe present invention.

An electronic apparatus 400 that utilizes as a light source a lightemitting device package including a phosphor having a core-shellstructure is provided in accordance with some embodiments of the presentinvention.

An electronic apparatus 400 that exhibits high color reproductioncapability by using a phosphor having a core-shell structure is providedin accordance with some embodiments of the present invention.

A phosphor having a core-shell structure can be used for controllingcolor coordinates in accordance with some embodiments of the presentinvention.

The above description and the accompanying drawings provide an exampleof the technical idea of the present invention for illustrative purposesonly. Those having ordinary knowledge in the technical field to whichthe present invention pertains will appreciate that variousmodifications and changes in form, such as combination, separation,substitution, and change of a configuration, are possible withoutdeparting from the essential features of the present invention.Therefore, the embodiments disclosed in the present invention areintended to illustrate the scope of the technical idea of the presentinvention, and the scope of the present invention is not limited by theembodiment. The scope of the present invention shall be construed on thebasis of the accompanying claims in such a manner that all of thetechnical ideas included within the scope equivalent to the claimsbelong to the present invention.

What is claimed is:
 1. A light-emitting device package, comprising: alight emitting device configured to emit light of a first mainwavelength band within a visible light wavelength band; a first phosphorincluding a first core and a first shell, the first core including afluorescent material capable of emitting light of a first wavelengthband different from the first main wavelength band of the light emittedfrom the light emitting device, wherein the first shell eliminates lightof a specific wavelength band or attenuates an intensity of light of thespecific wavelength band from the light of the first wavelength band toemit light of a second main wavelength band within the visible lightwavelength band; and a second phosphor including a second core, andwherein the first core is heavier than the first shell.
 2. Thelight-emitting device package of claim 1, wherein a combination of thelight emitting device, the first phosphor including the first core andthe first shell, and the second phosphor including the second coreimproves a gamut of pure colors emitted and exhibits high colorreproduction capability.
 3. The light-emitting device package of claim2, wherein a weight ratio of the first shell to the first core is 0.6 orless.
 4. The light-emitting device package of claim 3, wherein athickness of the first shell is less than a distance from a center ofthe first core to a surface of the first core.
 5. The light-emittingdevice package of claim 4, wherein the first shell includes at least onerare earth element in a lanthanum group.
 6. The light-emitting devicepackage of claim 5, wherein the first core includes at least oneselected from among (Sr,Ba,Mg)₂SiO₄:Eu, Al₅Lu₃O₁₂:Ce,(Sr,Ba,Mg)₂SiO₄:Eu, Y₃Al₅O₁₂:Ce, La₃Si₆N₁₁:Ce, (Sr, Ba, Eu)₂SiO₄:Eu,β-Sialon:Si_(6-z)Al_(z)O_(z)N_(8-z):Eu, Lu₃Al₅O₁₂:Ce, (Lu,Gd)₃Al₅O₁₂:Ce, and Y₃Al₅O₁₂:Ce (0.01<z<10).
 7. The light-emitting devicepackage of claim 6, wherein the first shell ranges in thickness fromapproximately 2,000 nm-500,000 nm.
 8. The light-emitting device packageof claim 7, wherein the light emitting device is a blue light emittingdevice and the first main wavelength band is a blue wavelength band,wherein the first phosphor is a green phosphor and the first wavelengthband is a green wavelength band, and wherein the second phosphor is ared phosphor and a second wavelength band emitted by the second core isa red wavelength band.
 9. The light-emitting device package of claim 1,wherein the second phosphor further includes a second shell, and aweight ratio of the first shell to the first core in the first phosphoris different from that of the second shell to the second core in thesecond phosphor.
 10. The light-emitting device package of claim 1,wherein the second phosphor further includes a second shell, and aweight ratio of the first shell to the first core in the first phosphoris identical to that of the second shell to the second core in thesecond phosphor.
 11. A light-emitting device package, comprising: alight emitting device configured to emit light of a first mainwavelength band within a visible light wavelength band; a first phosphorincluding a first core and a first shell, wherein the first coreincludes a fluorescent material capable of emitting light of a firstwavelength band different from the first main wavelength band of thelight emitted from the light emitting device, and wherein the firstshell eliminates light of a specific wavelength band or attenuates anintensity of light of the specific wavelength band from the light of thefirst wavelength band to emit light of a second main wavelength bandwithin the visible light wavelength band; and a second phosphorincluding a second core, wherein the second core includes a fluorescentmaterial capable of emitting light of a second wavelength band differentfrom the first main wavelength band of the light emitted from the lightemitting device, and wherein the first core is heavier than the firstshell.
 12. The light-emitting device package of claim 11, wherein acombination of the light emitting device, the first phosphor includingthe first core and the first shell, and the second phosphor includingthe second core improves a gamut of pure colors emitted and exhibitshigh color reproduction capability.
 13. The light-emitting devicepackage of claim 12, wherein the first shell includes at least one rareearth element in a lanthanum group.
 14. The light-emitting devicepackage of claim 13, wherein the first core includes at least oneselected from among (Sr, Ba, Mg)₂SiO₄:Eu, Al₅Lu₃O₁₂:Ce,(Sr,Ba,Mg)₂SiO₄:Eu, Y₃Al₅O₁₂:Ce, La₃Si₆N₁₁:Ce, (Sr, Ba, Eu)₂SiO₄:Eu,β-Sialon:Si_(6-z)Al_(z)O_(z)N_(8-z):Eu, Lu₃Al₅O₁₂:Ce, Gd)₃Al₅O₁₂:Ce, andY₃Al₅O₁₂:Ce (0.01<z<10).
 15. The light-emitting device package of claim13, wherein a weight of the first shell and a weight of the first coreare determined according to a weight ratio of the first shell to thefirst core to emit pure color light without degrading luminanceperformance.
 16. The light-emitting device package of claim 15, whereinthe weight ratio of the first shell to the first core is 0.6 or less.17. The light-emitting device package of claim 16, wherein the lightemitting device is a blue light emitting device and the first mainwavelength band is a blue wavelength band, wherein the first phosphor isa green phosphor and the first wavelength band is a green wavelengthband, and wherein the second phosphor is a red phosphor and the secondwavelength band is a red wavelength band.
 18. The light-emitting devicepackage of claim 11, wherein the second phosphor further includes asecond shell, and a weight ratio of the first shell to the first core inthe first phosphor is different from that of the second shell to thesecond core in the second phosphor.
 19. An electronic apparatus,comprising: a light emitting device package including: a light emittingdevice configured to emit light of a first main wavelength band within avisible light wavelength, a first phosphor configured to emit light of asecond main wavelength band different from the first main wavelengthband, and a second phosphor including a second core; and a drivingcircuit configured to drive the light emitting device, wherein the firstphosphor comprises: a first core including a fluorescent materialcapable of emitting light of a first wavelength band different from thefirst main wavelength band of the light emitted from the light emittingdevice, and a first shell, applied to a surface of the first core, andconfigured to emit light of the second main wavelength band within thevisible light wavelength band by eliminating light of a specificwavelength band from the light of the first wavelength band or byattenuating an intensity of the light of the specific wavelength band,and wherein the first core is heavier than the first shell.
 20. Theelectronic apparatus of claim 19, wherein a weight ratio of the firstshell to the first core is 0.6 or less, and wherein the first shellincludes at least one rare earth element in a lanthanum group.
 21. Theelectronic apparatus of claim 20, wherein the first core includes atleast one selected from among (Sr,Ba,Mg)₂SiO₄:Eu, Al₅Lu₃O₁₂:Ce,(Sr,Ba,Mg)₂SiO₄:Eu, Y₃Al₅O₁₂:Ce, La₃Si₆N₁₁:Ce, (Sr, Ba, Eu)₂SiO₄:Eu,β-Sialon:Si_(6-z)Al_(z)O_(z)N_(8-z):Eu, Lu₃Al₅O₁₂:Ce (Lu, Gd)₃Al₅O₁₂:Ce,and Y₃Al₅O₁₂:Ce (0.01<z<10).
 22. The electronic apparatus of claim 21,wherein the second core includes a fluorescent material capable ofemitting light of a second wavelength band different from the first mainwavelength band of the light emitted from the light emitting device,wherein the light emitting device is a blue light emitting device andthe first main wavelength band is a blue wavelength band, wherein thefirst phosphor is a green phosphor and the first wavelength band is agreen wavelength band, wherein the second phosphor is a red phosphor andthe second wavelength band is a red wavelength band, and wherein thesecond phosphor includes a second shell.
 23. The electronic apparatus ofclaim 19, wherein the second phosphor further includes a second shell,and a weight ratio of the first shell to the first core in the firstphosphor is different from that of the second shell to the second corein the second phosphor.